Device and process for storing and transferring strip-shaped products for use in making a tire cover

ABSTRACT

A device for storing and transferring strip sections of rubber products intended for making a tyre cover, comprising a storage cylinder mounted to rotate about a horizontal axis (A 4 ) of revolution on a frame which is in turn mounted on a support, comprising a flexible strip, forming a closed loop and circulating around part of the cylinder, and a set of guides, with the cylinder and the flexible strip being suitable for clamping a strip section. The frame may also be mounted to rotate on the support about a second axis (A 5 ) perpendicular to the axis (A 4 ) of revolution of the storage cylinder.

The invention relates to a process for handling strip-shaped products inorder to use them to make a tyre cover.

To make a cover of this kind, various different products are used, andthese are initially stored in the form of continuous strips wound ontostorage bobbins arranged in supply stations. These strips are unwoundand then cut into sections of predetermined length. The various sectionsare then wound around a building drum by being deposited one after theother.

Moreover, once some pairs of products are laid on the building drum,they are symmetrical with respect to a plane perpendicular to the axisof rotation of the drum and passing through the centre of the drum. Ifthe intention is to obtain the two sections from a single strip comingfrom a single supply station, then before depositing one of the twoproduct sections onto the drum it has to be pivoted by 180° about anaxis perpendicular to the plane of this same product section, which islaid flat, to obtain a section which is symmetrical with respect to thesection which does not undergo this pivoting. Once they are deposited,one after the other, on the left-hand and right-hand sides of thebuilding drum, the two product sections then have the desired symmetry.

The products referred to above may be rubber profiles, rubber strips orindeed plies formed from a rubber mix in which textile threads or metalcords are embedded, arranged parallel to one another and forming adefined angle with the longitudinal direction of the ply, these pliesbeing called for example “carcass reinforcement plies” or “belt plies”,depending on their position within the tyre.

Taking into account in particular the large number of different productsto be laid, the mass and volume of the ply sections, when making tyresof large dimensions, such as those intended for construction machineryor agricultural vehicles, most of the operations (comprising unwindingcontinuous strips from their respective supply stations, cutting themoff to form sections, turning them and transferring the said sections tothe building drum) remain manual to date and are somewhat onerous.

To automate these operations and to improve ergonomics, a large numberof technological solutions may be implemented.

Thus, it is possible to envisage the cooperation of a laying drum, whichis movable in the direction transverse with respect to the direction inwhich the products are unwound and comes into position on demand alongthe axis of servers, which are generally fixed, each comprising astrip-unwinding system, with a cutting system and a transfer system.These principles are disclosed for example in U.S. Pat. No. 3,654,828.

However, this solution has the result that the number of cutting andtransfer systems are multiplied, which substantially increases the costof an installation of this kind. Another approach, which is particularlyadvantageous, consists in installing one or more movable assembliescarrying out the cutting and then the transfer of the strip sectionsfrom the fixed unwinding stations of each of the products to a fixedlaying drum. A description of this kind of device can be found, by wayof example, in U.S. Pat. No. 4,504,337.

Because of the great length of the sections to be handled, thesetransfer assemblies generally make use of storage cylinders around whichthe section to be transferred is wound before being deposited on thelaying drum. Cylinders of this kind, which may be fixed or movable, aredisclosed in DE 27 40 609, U.S. Pat. No. 3,591,439 or indeed U.S. Pat.No. 3,654,828. The product is kept wound around the outer surface of thecylinder either by a pneumatic device establishing a negative pressurebetween the sole of the product and the surface of the cylinder or by aset of electromagnetic devices, where the products contain metalelements.

However, these systems are ill suited to handling sections of severalmetres weighing several tens of kilos, as is often the case for makingtyres intended for construction machinery or agricultural equipment.Moreover, the products whereof the final positions on the drum aresymmetrical, are unwound from two separate supply stations, which tendsto increase the number of stations and the size of the installation.

The object of the invention is specifically to find a solution which ishighly flexible to use in the handling of strip sections of great massand length.

To this end, the invention relates to a storage and transfer devicewhich is particularly suitable for storing product sections of highmass, comprising a storage cylinder mounted to rotate about a horizontalaxis of revolution on a frame which is in turn mounted on a support,characterised in that it has a flexible strip, forming a closed loop andcirculating around part of the cylinder, and a set of guides integrallyformed on the frame, with the cylinder and the flexible strip beingsuitable for clamping the strip section to be transferred.

Moreover, the frame of this device may be mounted to rotate on thesupport about a second axis perpendicular to the axis of revolution ofthe storage cylinder, which therefore enables the strip section to beturned by pivoting it by 180° before it is deposited on the buildingdrum.

The present description is intended to give non-restrictive details of atransfer and storage device and an installation having a device of thiskind in accordance with the invention, and to present variantembodiments allowing use to be adapted to various products orconfigurations of installations, this description being given withreference to the attached drawings, in which:

FIG. 1 is a plan or view from above of an installation having a deviceaccording to the invention;

FIG. 2 is a side view or elevation of the installation of FIG. 1, in adirection indicated in FIG. 1 by the arrow V; here, the installation isshown empty, that is to say without any product to lay;

FIGS. 3 and 4 are diagrammatic perspective views of a switching device;

FIG. 5 illustrates a diagrammatic view of a strip section before andafter it has been turned; and

FIGS. 6 to 11 are views similar to FIG. 2, illustrating the installationduring operation, and illustrating the successive steps of a process formaking tyres which makes use of a device according to the invention.

In the text below, like reference numerals designate like elementsillustrated in FIGS. 1 to 11.

The installation (1) as shown in FIG. 1 has, in the variant embodimentselected, a plurality of adjacent supply stations (2) which are arrangedin a direction (T) perpendicular with respect to the direction of supply(L). A cutting device (3), which is movable in the transverse direction(T), is displaced on rails (33 and 34) to come into position on demandin front of one of the supply stations (2). A storage and transferdevice (4) having a storage cylinder (40) is displaceable in translationon rails (54 and 55) in a direction perpendicular to the direction ofsupply, in order to be brought successively opposite the cutting device(3) and then opposite a receiving station (6) positioned upstream of abuilding drum (7).

FIG. 2 shows in detail the way each of these members is arranged.

The supply station (2) comprises a frame (20) on which is mounted abobbin (21) for storing a product in the form of a continuous stripsupported by a backing element (22); the storage bobbin is driven by amotor (not illustrated) about a horizontal axis A1 perpendicular withrespect to the direction of supply L. The backing element (22) isunwound about a first separating roll (23) which is mounted to rotate onthe frame (20) about an axis A2 parallel to A1, and ends by being woundaround a recovery spool (24) which is also mounted on the frame (20),rotating about an axis A3 parallel to A1 and A2. A conveyor belt (25)mounted on the frame (20) allows the product strip to be received andguided at the exit point from the separating roll.

In the variant embodiment presented, the cutting tool (3) is mounted ona movable carriage (30) having guide wheels (31) and motorised wheels(32) and is displaced in the transverse direction (T) on a rail (33) anda roll track (34) mounted on the frame (20). A set of conveyor belts(35) integrally formed on the carriage (30) allows the product strip tobe guided across the cutting device. A measuring system (notillustrated) allows the length of unwound strip to be determinedprecisely and the cutting to be controlled in order to obtain a productsection of the desired length. The cutting tool is adapted to the natureof the product to be cut.

The transfer and storage device (4) comprises a storage cylinder (40)mounted to rotate on a frame (49) about a horizontal axis A4 which isperpendicular to the direction of supply (L) This cylinder is surroundedby a flexible strip (45) forming a closed loop and circulating on a setof guides (46) mounted on the frame (49) along axes parallel to the axisA4. This set of guides may for example be formed by a set of pulleys.

The part of the cylinder (40) surrounded by the flexible strip locatedon the lower part thereof forms an angular opening of preferably between180° and 240°. The complementary part of the cylinder located in theupper portion of the cylinder (40) is left free. In all cases, thediameter of the cylinder (40) and the length of the part of thecircumference thereof in contact with the flexible strip will have to bedetermined such that this length is greater than the length of theproduct sections to be handled.

The cylinder (40) is driven by a motor (not illustrated), and when itrotates about its axis of revolution A4 it can drive the flexible strip(45) by friction in the manner of a driving pulley. The cylinder and theflexible strip are suitable for jointly driving by friction a section ofproduct strip held between them in order to wind this section around thecylinder.

A tensioning system (47, 48) ensures constant tension of the flexiblestrip and allows product sections of variable thickness and mass to beheld without deforming them. This system may be in the form of pneumaticjacks acting on the axes of pulleys selected for this purpose andmounted to slide in apertures, or indeed by calibrated weights.

In the example embodiment illustrated, the frame (49) of this device ismounted to rotate on a support (50) about a second axis (A5) which isvertical and perpendicular with respect to the axis of revolution (A4)of the storage cylinder, passing through the mid-line of the storagecylinder. In this way, it becomes possible, by pivoting by 180° aboutthe axis A5, to turn the strip section before depositing it on thebuilding drum. FIG. 5 shows in detail the position of a product sectionbefore it is turned (P) and after it is turned (P′) by 180° about anaxis (A0) which is perpendicular to the plane of the product and passesthrough its centre. The same result is obtained by performing a rotationof 180° of the frame (49) about the axis A5 after winding the section(P) around the storage cylinder (40) and then unwinding this samesection onto a receiving station (6) or a building drum.

The support (50) is mounted on a frame (51) of a movable carriage (5)displaced in the direction perpendicular to the direction of supply (L).This carriage has guide wheels (52) and motorised wheels (53) displacedrespectively on rails (54) and a roll track (55). The carriage allowsthe transfer and storage system to be positioned opposite the cuttingtool (3) and the storage bobbin (2) from which a product section is tobe drawn off. After this section has been loaded around the storagecylinder, the transverse displacement of the carriage to a predeterminedposition opposite the receiving station (6) or the drum (7) allows theproduct section to be unloaded onto the receiving station or the drum,pre-positioning it before it is deposited definitively onto the drum(7).

A switching device system (41 and 42) allows winding and unwinding ofthe product section around the cylinder (40) to be facilitated. FIGS. 3and 4 illustrate a switching device according to the invention. The arm(41) is mounted to pivot about an axis (A7) which is integrally formedon the frame (49) and parallel to the axis of rotation (A4) of thecylinder. It is equipped with an endless conveyor belt (411) driven by amotor (not illustrated) and circulating in a direction perpendicular tothe axis of pivoting (A7). In the closed position, as represented inFIG. 3, the end of the arm (412) is brought close to the surface of thecylinder (40). Here, the term “close” is understood to be the smallestpossible distance allowing contact between the end of the arm (412) andthe surface of the storage cylinder to be avoided while ensuring that aproduct section is transferred from the surface of the storage cylinderto the conveyor belt (411) of the storage arm (41) without harming theproduct. In the open position, as illustrated in FIG. 4, the free end(412) of the arm is at a distance from the surface of the cylinder (40).This distance must be large enough to allow a product section depositedon the surface of the cylinder to circulate freely.

The storage device serving as a support in the present description hastwo arms (41 and 42) arranged opposite one another on either side of thestorage cylinder and each equipped with a conveyor belt (411 and 421):This arrangement has proved particularly effective when the intention isto turn the product sections, as the switching devices (41 and 42) arealternately positioned at the entry point and exit point of the storageand transfer device.

Conveyor belts (43, 44) fixed to the frame (49) ensure that the productsection is transferred at the entry point or exit point of the transferand storage device (4) and circulate in the same direction as theconveyor belts with which the pivotal arms (41 and 42) they adjoin areequipped.

Downstream of the storage and transfer device (4) is arranged areceiving station (6) formed by a bench (61) having for example a set ofrolls mounted to rotate about transverse axes; these rolls may be freeor motorised, as desired. The bench (61) of the receiving station ismounted on a frame (63) and may be lifted with the aid of a jack (62) toleave free the course travelled by the transfer and storage device (4)when it is rotated about the axis A5.

The drum (7) onto which the product sections are wound one after theother using predetermined procedures and equipment is placed at the exitpoint of the receiving station. The drum (7) is mounted to rotate on aframe (70) about a horizontal axis (A6) perpendicular to the axis ofsupply (L).

The installation (1) also comprises a control unit (8) which controls,in particular:

-   -   unwinding and rewinding of the storage bobbin (2);    -   circulation of the conveyor belts (25, 35, 44, 421, 411, 43,        61), with adjustment of their respective linear speeds;    -   transverse displacement of the cutting tool (30) and the        carriage (5);    -   measurement of the length of the strip;    -   actuation of the cutting tool (3);    -   driving of the storage cylinder (40) and adjustment of its        tangential speed;    -   regulation of the tension of the flexible strip (47, 48);    -   pivoting of the arms of the switching device system (41, 42);    -   lifting of the bench of the receiving station (6);    -   turning of the frame (49) about the axis A5;    -   rotation of the drum (7).

The result is the automation of a number of the operations for handlingthe product strips, in particular supplying them from the storagebobbins (2), cutting them into product sections and transporting andturning the sections to bring them close to the building drum (7).

The variants on installation are numerous and may contribute tomanagement of the transfer and storage device (4).

Thus, a first variant (not illustrated) consists in fixing the cuttingtool (3) to the frame (49) of the transfer and storage device, with thecarriage (5) ensuring transverse displacement simultaneously of theframe (49) and the cutting tool and the associated conveyor belts (35).

It is also possible, if it proves necessary to turn product sectionswhich are symmetrical and if the mass of these sections is notexcessive, to use a storage cylinder equipped with a magnetic system, ifthe products to be handled contain metal elements, or a pneumatic systemallowing the product sections to be held on the surface of the transfercylinder by negative pressure.

Similarly, if the number of products to be laid is small, it may proveadvantageous to hold the frame (49) in a fixed position about the axisA5 and to supply from two different bobbins products which, once theyhave been laid, are symmetrical with respect to the plane perpendicularto the axis of the drum and passing through its centre. In this case, ifthe nature of the products to be handled lends itself thereto, it mayonly be necessary to use a single switching device (41) located at theexit point of the transfer and storage device.

It is also possible to envisage the product being in the form of a stripwhich has already been cut up into sections of predetermined length. Inthis case, the supply station and the transfer means located upstream ofthe transfer and storage station are adapted to bring these pre-cutsections directly to the process of transfer and storage where theturning is performed, if necessary, and then to unload the productsection to a defined transverse position on the receiving station or thedrum.

When the number of sections to be laid becomes significant, the use of asecond handling and storage device (4′) as illustrated in FIG. 1 or aplurality of such devices may contribute to making an improvement to theperformance of the installation.

It is also possible to omit the receiving station. In this case, theproduct sections are deposited directly from the transfer and storagedevice (4) onto the drum (7).

Similarly, instead of being aligned side by side, the supply stationsmay be distributed around a rotary conveyor which is actuated in orderto bring the selected supply station(s) opposite the transfer andstorage device(s).

It is also possible to provide for a plurality of product sectionsarranged parallel to one another to be stored in the transfer device(4). These sections may come from a single storage bobbin or differentstorage bobbins. By making a few minor modifications to the transfer andstorage device it is possible to introduce these sections into thestorage device successively and to draw them off one after the other,towards the receiving station, in different transverse positions. Allthat needs to be done for this is to equip the storage device with aplurality of switching device systems as described above, arranged sideby side and parallel to the axis of revolution of the storage cylinder,with each switching device system being actuated independently of theadjacent storage system in order to enable a section to be transferredto the storage device or from the storage device at the same time. Itgoes without saying that the width of the storage cylinder (40) isadjusted accordingly.

By way of illustration, the process making use of an installation (1)comprising a handling and storage device (4) of this kind comprises thesteps described below and illustrated in FIGS. 6 to 11:

-   -   With reference to FIG. 6, as a function of how far assembly of        the products of the tyre cover being made has advanced, the        supply station (2) capable of delivering the strip of material B        intended for laying on the building drum (7) is selected.    -   Then the cutting tool (3) and the carriage (5) supporting the        storage device (4) are moved on their respective circulation        tracks (33, 34, 54, 55) in order to come into position opposite        the selected supply station (2). The arms (42 and 41) are        lowered. The conveyor belts (25, 35, 44 and 421) form an        extension of one another in order to create a single conveying        path.    -   With reference to FIG. 7, the arm (41) is then lifted and a        length of strip B is transferred in the direction of supply (L)        from the supply station (2) to the storage device (4), passing        perpendicular with respect to the cutting tool (3). To this end,        the storage bobbin (21) is unwound, the backing element strip        (22) then being wound onto the recovery spool (24), while the        product strip B circulates successively on the conveyor belts        (25, 35, 44 and 421). The cylinder (40) is driven in rotation        about its axis A4 and in turn drives the flexible strip (45) by        friction. The strip of material B comes up against the upper        surface of the cylinder (40), following its rotation by passing        along the course left free between the end of the arm (41) and        the surface of the cylinder (40). The strip of product B then        comes into engagement with the flexible strip (45), which holds        it flat against the cylinder (40) and drives it by friction        together with the storage cylinder (40), to ensure that it is        wound around the latter.    -   With reference to FIG. 8, when the unwound length corresponds to        the length desired, the cutting tool (3) is actuated to create a        section (P), which continues to be wound around the storage        cylinder (40) until the product section (P) is captured in its        entirety between the flexible strip (45) and the cylinder (40).        So that the transverse movement of the cutting tool is not        impeded, a brief rewinding of the strip of material B onto its        storage bobbin is performed, until the free end of the strip B        rests on the conveyor belt (25).    -   With reference to FIG. 9, the cutting tool (3) is moved        transversely and comes into position opposite another supply        station. The arm (41) is lowered and the storage and transfer        system (4) can then be brought opposite the receiving station        (6) by moving the carriage (5) on its rails (54 and 55). The        transverse position will be selected appropriately in order to        pre-position the product section (P).    -   Should it prove necessary, the frame (49) is pivoted by 180°        about the axis A5 so that the product section is turned. In        order to free sufficient space to allow this turning, the bench        (61) of the receiving station (6) may be lifted further for a        moment with the aid of the jack (62). Care should also be taken        that the frame (49) is not opposite the cutting station (3)        during this operation.    -   With reference to FIG. 10, the arm (42) is lifted and the bench        (61) of the receiving station (6) is realigned with the conveyor        (43) of the storage and transfer station. The cylinder (40) is        rotated and the section (P) is drawn off the transfer and        storage device, circulating on the conveyor belts (411, 43), and        then transferred to the bench (61) of the receiving station (6).    -   With reference to FIG. 11, the section (P) is finally deposited        on the building drum (7) before being rotated.    -   The arm (42) is lowered and the installation is then ready to        perform the transfer of a new product section.

1-12. (canceled)
 13. A device for storing and transferring rubber stripsections for making a tire cover, comprising a storage cylinder mountedfor rotation about a substantially horizontal axis of revolution on aframe, the frame mounted on a support for rotation about a substantiallyvertical axis.
 14. A storage and transfer device according to claim 13,further including a flexible strip forming a closed loop and movablearound part of the cylinder, and a set of guides for guiding theflexible strip, with the cylinder and the flexible strip arranged forclamping and frictionally driving a rubber strip section held betweenthe cylinder and the flexible strip to wind the rubber strip sectionaround the cylinder.
 15. A storage and transfer device according toclaim 14, wherein the support is mounted on a movable carriage.
 16. Astorage and transfer device according to claim 15, wherein the movablecarriage is guided movably along a rail.
 17. A storage and transferdevice according to claim 15, wherein the movable carriage carries acutting tool disposed upstream of the storage cylinder with reference toa direction of movement of the rubber strip sections.
 18. A storage andtransfer device according to claim 13, further including a switchingdevice for driving a strip section to and from the storage cylinder. 19.A storage and transfer device according to claim 18, wherein theswitching device comprises at least one movable arm mounted to pivot onthe frame about an axis oriented parallel to the axis of rotation of thestorage cylinder between: a closed position, in which a free end of thearm is brought close to the surface of the storage cylinder, and an openposition, in which the free end is at a distance from the surface of thestorage cylinder.
 20. A storage and transfer device according to claim19, wherein the arm includes an endless conveyor belt circulating in adirection perpendicular to the pivot axis of the arm.
 21. A storage andtransfer device according to claim 18, wherein the switching deviceincludes two movable arms arranged opposite one another on respectivesides of the storage cylinder.
 22. A storage and transfer deviceaccording to claim 14, further including a tensioning mechanism forholding the flexible strip at constant tension.
 23. A storage andtransfer device according to claim 13 wherein the storage cylinder ismotor-driven and frictionally drives the flexible strip.
 24. A storageand transfer device according to claim 13 wherein the substantiallyhorizontal and vertical axes intersect one another.
 25. A tire-makingfacility comprising: a plurality of supply stations arranged adjacentone another in a first row, the supply stations containing respectiverubber sections for making a tire, a plurality of tire-building sitesarranged adjacent one another in a second row oriented substantiallyparallel to the first row, a storage-and-transfer device movable alongand between the first and second rows, the device including: a movablecarriage, a frame mounted on the carriage for rotation about asubstantially vertical axis, and a storage cylinder mounted on the framefor rotation about a substantially horizontal axis for storing a rubbersection thereon, wherein the storage-and-transfer device is movablealong the first and second rows to receive a rubber section from aselected supply station onto the storage cylinder and transfer therubber section to a selected tire-building site from the storagecylinder after rotating the frame by about 180 degrees about thesubstantially vertical axis.
 26. The tire-making facility according toclaim 25 wherein the substantially horizontal and vertical axesintersect one another.
 27. A process for making tires utilizing a devicefor storing and transferring rubber sections for making a tire, thedevice including a frame rotatable about a substantially vertical firstaxis, and a storage cylinder mounted on the frame for rotation about asubstantially horizontal second axis, the process comprising the stepsof: A. winding from a supply station a rubber section of predeterminedlength around the supply cylinder while rotating the supply cylinderabout the second axis, B. pivoting the frame by about 180 degrees aboutthe first axis, C. positioning the device opposite a tire building site,and D. subsequent to steps B and C unwinding the rubber section from thestorage cylinder and transferring the rubber section to thetire-building site.
 28. The process according to claim 27 wherein step Aincludes positioning the frame adjacent a selected one of a number ofsupply stations, and step C comprises moving the frame from the selectedsupply station to a location opposite a selected one of a number oftire-building sites.